rebase: improve error messages about dirty state

If you have unstaged changes in your working tree and try to
rebase, you will get the cryptic "foo: needs update"
message, but nothing else.  If you have staged changes, you
get "your index is not up-to-date".

Let's improve this situation in two ways:

 - for unstaged changes, let's also tell them we are
   canceling the rebase, and why (in addition to the "needs
   update" lines)

 - for the staged changes case, let's use language that is a
   little more clear to the user: their index contains
   uncommitted changes

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-rebase.sh b/git-rebase.sh
index ea7720d3e29650b09a2805410a08f19d73f287f5..ebd4df3a0e821ddcfd1eabfcaac17f854e172a85 100755 (executable)
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -332,11 +332,14 @@ else
 fi
 
 # The tree must be really really clean.
-git update-index --ignore-submodules --refresh || exit
+if ! git update-index --ignore-submodules --refresh; then
+       echo >&2 "cannot rebase: you have unstaged changes"
+       exit 1
+fi
 diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
 case "$diff" in
-?*)    echo "cannot rebase: your index is not up-to-date"
-       echo "$diff"
+?*)    echo >&2 "cannot rebase: your index contains uncommitted changes"
+       echo >&2 "$diff"
        exit 1
        ;;
 esac